Hamburg police found the white Mercedes minivan parked blocking the entrance to a cemetery in the Bilstedt area of the city. The child, who has been identified only as Jeremie, was nowhere to be found.
Helicopters have been sent out to search nearby forest areas, as Jeremie's foster parents told officers that they thought he could be hiding among the trees. The parents did not say why, the Hamburger Abendblatt newspaper reported.
This was not the first time that Jeremie has run away from his foster parents, nor is it the first time that he has stolen a car. A prior incident ended in him crashing a vehicle, also en route to Hamburg.
Police said they believed Jeremie had planned his escape from his home town of Lübtheen in Mecklenburg Western-Pomerania, waiting until his guardians' backs were turned to grab their minivan keys.
Police said the boy is 1.5 metres tall and strong, for an 11-year-old.